CMP stands for "Convention Mission Pack". These are one-shot adventures that are exclusive to the convention circuit for at least a year. They're not tied into the main Seasonal Missions plot, usually, and they can take place anywhere and involve almost anything. Not being tied to the Season storyline makes them easier for convention players who may not be familiar with Missions to just drop in and play.
They still count as a Mission, you still get full karma and money, all that good stuff.
Bull